A chip-type coil as shown in FIG.5 has hitherto been used. The chip-type coil has at both vertical sides of a winding portion 2a flanges 2b and 2c, a winding 4 is wound around the winding portion 2a and a pair of terminal electrodes 6a and 6b for mounting the coil on a printed substrate or the like are formed directly at both lateral sides of the lower flange 2c, the wiring 4 being electrically connected at both ends thereof to both the terminal electrodes 6a and 6b by use of soldering ( not shown ). The terminal electrodes 6a and 6b are formed of electrically conductive paste, such as silver paste or silver-palladium paste, printed on the surface of the flange 2c and baked.
The above-mentioned chip-type coil, however, forms directly on the core 2 the terminal electrodes 6a and 6b Which are superior in conductivity, whereby the problem is created in that the eddy current loss at the terminal electrodes 6a and 6b causes Q-deterioration.
In detail, as shown in FIG.6, the magnetic flux 8 caused at the wiring 4 passes through the terminal electrodes 6a and 6b formed at the flange 2c, at which time an eddy current flows in the terminal electrodes 6a and 6b. The eddy current i can generally be given in rot i=-K(dB/dt), where K is an electrical conductivity: inverse number of specific resistance .rho., and B, flux density. In this case, the conventional terminal electrodes 6a and 6b are formed of silver or silver - palladium and are larger in the conductivity K, so that the eddy current i is larger and an energy loss thereby causes the Q-deterioration.
Also, in order to prevent solder-reaching caused when soldering, it is preferable to apply metal plating of nickel, tin, solder or copper on the surface of the electrode formed of silver or the like. However, the above-mentioned chip-type coil, when metal plating is applied on the surface of terminal electrodes 6a and 6b, further increases in Q-deterioration, thereby creating the problem in that the metal plating is not applicable to the terminal electrodes.